Ortlieb's extensive experience earned by making some of the finest cycling bags and panniers shows through and through with the release of their new bikepacking bag line. The Ortlieb Bikepacking Seat Pack is a large, adjustable saddlebag that uses a waterproof design that weighs only 325 grams. The unique air release valve is a first of a kind feature in the bikepacking bike industry. Simply open the release valve and let out excess air which allows for much tighter compression.